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United States Patent |
5,335,564
|
Vinciguerra
|
August 9, 1994
|
Cam for revolving dobby
Abstract
A cam for a revolving dobby includes a plate with an upwardly extending
protective external edge, the external edge has two peripherally located,
mutually opposite notches, key levers are associated with the plate and
are protected by the external edge, thrust teeth on the auxiliary and
drive pushers cooperate with the key levers. The thrust tooth of the drive
pusher is rotatable hinged relative thereto and is rotated on the same
axis as the auxiliary pusher, springs cooperate with the auxiliary and
drive pushers to engage the key levers via one of the notches on the
plate.
Inventors:
|
Vinciguerra; Costantino (Florence, IT)
|
Assignee:
|
Nuovopignone - Industrie Meccaniche e Fonderia S.p.A. (Florence, IT)
|
Appl. No.:
|
021777 |
Filed:
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February 24, 1993 |
Foreign Application Priority Data
| Feb 25, 1992[IT] | MI92A000409 |
Current U.S. Class: |
74/567; 74/569; 139/66R; 139/76; 139/455 |
Intern'l Class: |
D03C 001/00; F16H 053/00 |
Field of Search: |
74/567,568 R,569,575,578
139/66 R,76,455
|
References Cited
U.S. Patent Documents
3180366 | Apr., 1965 | Hoenig | 139/66.
|
3207186 | Sep., 1965 | Hoenig | 139/66.
|
3724510 | May., 1973 | Kleiner | 139/66.
|
4329458 | Jul., 1983 | Gummeringer | 74/567.
|
4441528 | Apr., 1984 | Julich | 139/66.
|
4461325 | Jul., 1984 | Palan et al. | 139/68.
|
4535641 | Aug., 1985 | Kriz et al. | 74/569.
|
4625575 | Dec., 1986 | Le Bras | 74/567.
|
4730641 | Mar., 1988 | Schwarz | 139/76.
|
4803889 | Feb., 1989 | Harris | 74/568.
|
4854236 | Aug., 1989 | Thunker et al. | 74/569.
|
4905738 | Mar., 1990 | Kleiner | 139/76.
|
4926707 | May., 1990 | Yamada | 74/567.
|
4932277 | Jun., 1990 | Beaux | 74/569.
|
5055001 | Oct., 1991 | Natwick et al. | 74/569.
|
5259419 | Nov., 1993 | Vinciguerra et al. | 139/66.
|
Foreign Patent Documents |
487407 | Dec., 1953 | IT | 74/569.
|
Primary Examiner: Luong; Vinh T.
Attorney, Agent or Firm: Morgan & Finnegan
Claims
I claim:
1. A cam and dobby apparatus comprising,
a dobby and an intermittent-motion drive shaft including longitudinally
extending, oppositely positioned grooves;
a cam and plate member, said cam being positioned between said
intermittent-motion drive shaft and a head of a main connecting rod that
is installed idling on said intermittent-motion drive shaft, said plate
member having a peripheral edge that extends outwardly from a surface of
said plate member and includes oppositely positioned notches therein,
first and second spring biased key levers pivotally connected to the
surface of said plate member, one of said key levers having a first end
that can be received by and cooperates with one of said grooves to lock
said cam in rotatable position with said intermittent-motion drive shaft,
said key levers each having second free ends terminating adjacent to said
notches, said second free ends being supported and protected by said
outwardly extending peripheral edge of said plate member; and
a drive pusher and a rotatably hinged auxiliary pusher mounted on a common
axis, thereby superimposing said drive pusher on said auxiliary pusher,
each of said drive and auxiliary pushers have a thrust tooth at one end
thereof that can be received by either of said notches, first spring means
urging one end of said auxiliary pusher towards a fixed support and said
auxiliary pusher thrust tooth into engagement with one of said notches
and, second spring means engaging a shoulder of said drive pusher to force
said thrust tooth of said drive pusher into said notch to engage one of
said key levers and to disengage said first end of said key lever from
said groove of said shaft.
2. An apparatus according to claim 1, wherein said plate is ring-shaped and
concentrically disposed about said cam.
Description
FIELD OF THE INVENTION
The present invention relates to a novel cam for a revolving dobby which,
by preventing any sticking between the dobby organs consequent to abnormal
situations deriving from wrong assemblies or incomplete key disengagement
or engagement (keying) operations, or from fortuitous events of cam
dragging due to the presence of foreign bodies entered between adjacent
cams, secures an absolute safety of the dobby against any breakage risks
even in the case when any of said exceptional situations arises, and
furthermore makes it possible the same dobby to be constructed more simply
and with greater precision, with consequent savings in manufacturing
costs.
More specifically, the invention relates to an improvement in the cam used
in our prior European Patent Appln. Public. No. 0 525 862 published on
Feb. 3, 1993.
BACKGROUND OF THE INVENTION
As known from said prior patent application, each main connecting rod of
the revolving dobby is mounted with its idle head on the
intermittent-motion drive shaft which drives said dobby to revolve,
through a cam which, by being interposed between said shaft and said main
connecting rod head, is locked in its position by the action of the thrust
tooth of an auxiliary pusher which, by being rotatably hinged onto the
fixed body of the revolving dobby, cooperates with either of two radial,
mutually opposite notches provided on the periphery of the same cam, or is
made integral with said shaft by two swinging, mutually opposite keying
levers pivotally installed on said cam and cooperating with each other at
one of their ends, wherein a key is present which is urged by two springs
to enter one from two, also radial, mutually opposite grooves provided in
the drive shaft, with the disengagement of said key from the relevant
groove being accomplished thanks to the cooperation of the thrust tooth of
a drive pusher, also rotatably hinged onto said fixed body of the
revolving dobby, with one of the free ends of said keying levers.
On the other hand, in as much as the need for locking in position the cam,
and consequently the relevant main connecting rod, only arises
simultaneously with the above said key disengagement, the movements of
revolution of said auxiliary and drive pushers are always produced
simultaneously through one single cam system.
Such a structure known from the prior art offers considerable advantages,
but, unfortunately, is not absolutely free from risks of damaging its own
organs under very special circumstances.
In fact, if, owing to an assembling mistake, the cam is not installed in
such a way that either of both said locking notches thereof is in
correspondence of said tooth of the auxiliary lock pusher so as to be
capable of cooperating with it and consequently said tooth of the drive
pusher is not in such a position as to be capable of cooperating with the
free end of one of both key engagement levers, a subsequent motion of both
pusher teeth towards the cam would generate, upon the revolution of the
same cam, an interference between said mechanical parts, with consequent
breakages.
On the other hand, a possible incomplete operation of key disengagement
attained by moving said teeth of both pushers towards the cam in order to
lock said cam in its position, leaving the key still partially inside the
groove provided along the drive shaft, would keep said cam revolving and
the cam, by interfering with the pushers in lowered position, would cause
the same drawbacks as said above.
In the same way, an accidental dragging of the cam owing to various
reasons, such as foreign bodies entering between adjacent cams, by causing
an angular offset in the alignment between the tooth of the auxiliary
pusher and the relevant locking notch and consequently between the tooth
of the drive pusher and the end of the relevant keying lever, would
unavoidably cause fatal sticking events between the above said mechanical
organs.
Summing-up, the presence, on the peripheral edge of the cam, of two radial
locking notches which must necessarily be provided in corresponding
extensions of the same cam, showing more or less vertical walls, can
cause, in certain abnormal situations, fatal sticking events to occur
between said auxiliary pusher and said drive pusher and said walls of the
locking notches.
OBJECTS AND SUMMARY OF THE INVENTION
The purpose of the present invention precisely is of obviating the above
said drawbacks and hence supplying a cam for a revolving dobby, which
secures always a perfect operation without any sticking events occurring
between same dobby organs, independently of any abnormal circumstances
which may possibly arise.
The above purpose is substantially achieved thanks to the above said
asperities shown by the locking notches, which may cause sticking events
to occur, being replaced by a plate, preferably a ring-shaped plate, with
a jutting upwards protection external edge which, by being integral with
the same cam, supports and protects, inside its jutting upwards edge, both
said key engagement ("keying") levers, and furthermore is provided with
two radial, mutually opposite notches which are exactly provided opposite
to the free ends of said keying levers, with each of said keying levers
cooperating with the thrust teeth of both the auxiliary and drive pushers
which, for that purpose, are arranged superimposed to each other, and
operate in the same direction.
In fact, in that way, no events of organ sticking may occur any longer,
because, under abnormal circumstances, the movement towards the cam of the
thrust teeth of the auxiliary pusher and of the drive pusher will be
prevented now by said jutting upwards protection edge of said plate, which
will oblige said teeth to slide, with pressure, along the external surface
of said edge without interfering with the mobile dobby organs situated
inside said jutting upwards edge, with which they will be capable of
cooperating only in correspondence of said radial, mutually opposite,
grooves of said plate, i.e., in their correct angular operating positions.
In this regard is then evident that, in order to allow the drive pusher to
absorb, without breakages, that portion of movement which, by being forced
by the drive cam system, is prevented by the above said protection edge of
said plate, the tooth of said drive pusher must be made urged by a
preloaded spring, i.e., the above said tooth is made rotatable on the same
axis of the drive pusher and is kept urged by a preloaded spring against
the shoulder integral with said drive pusher and relative to the auxiliary
pusher.
Summing-up, the cam for revolving dobby which, interposed between t he
intermittent-motion drive shaft which drives said dobby and the head of
one of the main connecting rods mounted idling on said shaft, is locked in
its position by the action of the thrust tooth of an auxiliary pusher
which, rotatably hinged on the fixed body of the revolving dobby and urged
by a proloaded spring against a shoulder integral with the drive pusher,
cooperates with one of two radial, mutually opposite notches provided on
the periphery of the same cam, or is made integral with said shaft by two
swinging, mutually opposite keying levers pivotally installed on said cam
and cooperating with each other at one of their ends, wherein a key is
present which is urged by two springs to enter one from two, also radial,
mutually opposite grooves provided in the drive shaft, with the
disengagement of said key from the relevant groove being accomplished
thanks to the cooperation of the thrust tooth of said drive pusher, also
rotatably hinged onto the same axis of said auxiliary pusher and urged by
a spring against a fixed shoulder, with one of the free ends of said key
engaging levers, is characterized according to the present invention in
that with it a plate is integral, which is provided with a jutting upwards
protection external edge, which supports and protects, inside its jutting
upwards edge, both said key engagement ("keying") levers, and furthermore
is provided, on its peripheral edge, exactly opposite to the free ends of
said keying levers, with said two radial, mutually opposite notches, each
of which cooperates with both the thrust tooth of said auxiliary pusher
and the thrust tooth of said drive pusher, which, for that purpose, are
arranged superimposed to each other, and operate in the same direction,
with said thrust tooth of said drive pusher being hinged with possibility
of rotation relatively to said drive pusher on the same axis of said
auxiliary pusher and being kept urged by a preloaded spring against said
shoulder integral with the drive pusher.
Then according to a preferred embodiment of the present invention, said
plate with jutting upwards protection edge is in the form of a ring
concentric with said cam.
The invention is better explained now by referring to the accompanying
drawings, which illustrate a preferred form of embodiment given for merely
illustrative, non-limitative purposes because technical or structural
variants may always be supplied without departing from the scope of the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partial perspective view of a revolving dobby adopting a cam
made according to the invention;
FIG. 2 shows a side view, on a different scale, of the portion of revolving
dobby of FIG. 1;
FIG. 3 shows an analogous view to FIG. 2, in another operating step of the
revolving dobby;
FIG. 4 shows an analogous view to FIG. 2, an operating step of the
revolving dobby in the presence of an abnormal situation.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the Figures, with 1 one of the main connecting rods of the
revolving dobby is indicated, whose foot 2 is hinged onto the respective
main lever 3 and whose head 4 is mounted idling, through the interposition
of a cam 5, on the dobby drive shaft 6 which is driven to move with
intermittent motion, more precisely with a revolving motion with pauses
after every rotation of 180.degree.. Said cam 5 is integral with a plate 7
of substantially ring shape, which is provided with an external jutting
upwards edge 8 which acts as a protection edge for both keying levers 9
and 10 which, pivotally hinged, mutually opposite, onto said plate 7,
cooperate with each other at one of their ends wherein a key 11 is
provided which is urged by springs 12 to enter one of two radial, mutually
opposite grooves 13 and 14 provided along the drive shaft 6.
Opposite to the free ends, respectively 9' and 10', of both said keying
levers 9 and 10, the plate 7 is furthermore provided, on its peripheral
edge, with the two radial, mutually opposite notches 15 and 16, each of
which is suitable for cooperating with the thrust teeth 17 and 18,
superimposed to each other and acting in the same direction, respectively
of the auxiliary pusher 19 and of the drive pusher 20 which, by being
hinged onto a same shaft 21 parallel to the drive shaft 6, are actuated,
in a known way, by striking bars 22 and 23 driven by cam drive means not
displayed in the figures.
Furthermore, in as much as said pushers 19 and 20 reciprocate along
different length paths, because, whilst the auxiliary pusher 19 must only
slide its tooth 17 into the notch 15 or 16, the drive pusher 20 must be
capable of continuing its movement through said notch in order to be able
to urge, with its tooth 18, the free end 9' of the keying lever 9, and
consequently cause the key 11 to swing out from the groove 13, as
illustrated in FIG. 3, the auxiliary pusher 19 is urged towards a shoulder
24, integral with the drive pusher 20, by a preloaded spring 25 provided
between both said pushers, whilst the drive pusher 20 is urged by the
spring 26 against the stationary shoulder 27 so as to keep the thrust
teeth 17 and 18 out from said external edge 8, as illustrated in FIG. 2.
On the other hand, in order to allow the drive pusher 20 to move along its
whole stroke imposed by said cam drive means when, in the presence of a
whatever abnormal situation, its tooth 18, by not being any longer
opposite to one of notches 15 or 16, comes to urge, together with the
tooth 17 of the auxiliary pusher 19, onto the external surface of the edge
8 as illustrated in FIG. 4, said tooth 18 is made integral with an arm 28
which, by being pivotally hinged onto said shaft 21, is urged against said
shoulder 24 by a pressure spring 29 acting between said arm 28 and said
drive pusher 20. In that way, in fact, the longer stroke of the drive
pusher 20 is made possible by the higher compression of said spring 29
(see, again, FIG. 4).
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